The rapid popularization of the hand-held wireless communication terminal device raises higher requirements for the power consumption of the radio frequency receiving module. The structure of a double-conversion receiver uses two frequency conversions, and achieves good performances in both the image rejection and power consumption aspects, so that it is widely used in the low power consumption radio frequency receiving circuits. Most traditional double-conversion radio frequency front ends use combinations of active and passive frequency mixing, wherein band-pass filtering is performed after a first frequency conversion, and then a receiving signal is shifted to a base band by means of a second orthogonal frequency conversion.
In recent years, with the continuous decreasing of process dimension and increasing drive towards low power consumption, designers start to try a design method for a radio frequency receiving circuit in a near-threshold voltage condition. For the traditional double-conversion radio frequency receiving front ends, when the power supply voltage decreases below 0.6 V, it is very difficult for an active frequency-mixing circuit therein to obtain sufficient voltage margin.